In the absence of a block size cap miners can be supported using network assurance contracts. It's a standard way to fund public goods, which network security is, so I am not convinced by that argument.

I feel these debates have been going on for years. We just have wildly different ideas of what is affordable or not.

Perhaps I've been warped by working at Google so long but 100,000 transactions per second just feels totally inconsequential. At 100x the volume of PayPal each node would need to be a single machine and not even a very powerful one. So there's absolutely no chance of Bitcoin turning into a PayPal equivalent even if we stop optimizing the software tomorrow.

But we're not going to stop optimizing the software. Removing the block cap means a hard fork, and once we decided to do that we may as well throw in some "no brainer" upgrades as well, like supporting ed25519 which is orders of magnitude faster than ECDSA+secp256k1. Then a single strong machine can go up to hundreds of thousands of transactions per second.

The cost of a Bitcoin transaction is just absurdly low and will continue to fall in future. It's like nothing at all. Saying Bitcoin is going to get centralized because of high transaction rates is kinda like saying in 1993 that the web can't possibly scale because if everyone used it web servers would fall over and die. Well yes, they would have done, in 1993. But not everyone started using the web overnight and by the time they did, important web sites were all using hardware load balancers and multiple data centers and it was STILL cheap enough that Wikipedia - one of the worlds top websites - could run entirely off donations.